While supporting and praising the process of scientific discovery, society has neglected the process of disseminating information of these discoveries. This government neglect is particularly unfortunate in that economic theory suggests that the private sector will systematically underinvest in informaton dissemination. We propose to develop and estimate models of the use and value of automated bibliographic systems as a first step toward understanding the more general problem. A two level model is developed, with the first concerned with the diffusion of information about ERIC and MEDLINE among individuals and their usage rates of these systems. The second is concerned with these same questions for libraries or other subscribing institutions. The first model will be summed across individuals to provide the foundation for the second. User surveys will provide the data base in estimating the models of individuals. Detailed monthly usage data kept by the National Library of Medicine will provide the data base in estimating the institutional model. The simplest diffusion models will be epidemiologic in character, with complications introduced by individual's characteristics concerning the profitability of adoption, ease of adoption, nonrandom and nonuniform networks of communication among individuals and institutions, and the decision processes involved in becoming subscriber. Usage will be modeled as a function of user and institution characteristics. With these results, we will estimate the private and social value of these automated bibliographic systems. These results will also be used to trace out implications for subsidy of the systems and for such details of their operation as number of users to be served, number of citations to be kept in memory, and quality of service. Finally, the implications of this study of ERIC and MEDLINE will be related to the more general problem of information dissemination.